Generally, this kind of operating lever, as disclosed in Japanese Utility Model Publication No. Sho 57-20, 477, is provided with a fixing member fixed to the bicycle frame and having a cylindrical lever shaft, a lever body provided with a boss which has a wire-winding groove for winding therein a control wire connecting with a derailleur and is supported rotatably to the lever shaft, a mounting screw screwable with a threaded bore provided at the center of the lever shaft, and a spring washer interposed between the boss of the lever body and the head of the mounting screw, the boss being fitted rotatably onto the lever shaft, the spring washer abutting against one side surface of the boss, and the mounting screw tightly screwing with the threaded bore at the lever shaft, thereby bringing the spring washer into pressure-contact with the one side surface of the boss to apply to rotation of the lever body a resistance overcoming a return spring at the derailleur and maintaining the position of the operated lever body.
In such a conventional operating lever, the mounting screw thus tightened to apply the rotational resistance to the lever body cannot be tightened until locked.
As a result, repetition of the lever operation loosens the mounting screw, thereby creating the situation that the lever body cannot be maintained in the operated position.
Also, the boss is subjected only at a side surface of limited surface area to react with the rotational resistance through the spring washer, whereby a sufficient surface area for generating the resistance is not ensured, resulting in large variations in resistance during screwing of the mounting screw, thereby creating the problem of making it difficult to obtain a fine adjustment of the rotational resistance to the lever body.